Pneumatic hammer.



H. F. JONES, l. E. LANE I E. M. LILLIE.

PNEUMATIC HAMMERL APPLICATION FILED IuIIEzI. I9Is.

1,259,499. Patnted Mar. 12, 1918.

2 SHEETS-SHEET L UUOOUD i l- Y M i@ INVENTORS 2722K 7272.615

wITNIassES ATTORNEY Patented Mar. 12, 1918.

2 SHEETS-SHEET 2.

H. F. JONES, J. E. LANE & E. M. LILLIE.

PNEUMATIC HAMMER.

APPucAnoN man JuNEzl, 191e. 1,259,469.

` WITNESSES ATTORNEY NETE@ @FATE f ATENT FFQE.

HUGH n. JoNns, JOHN E. LANE, AND EDWARD ivi. DID'LIE, or RAY, AitizoN-A.

PNEUMATIG HAMMER.

Specification of Letters Patent. Patented Mar, 1918.

Application filed June 21, 19'16. Serial No. 104,947.

To all whom t may concern:

Be it known that we, HUGH F. JONES, JOHN E. LANE, and EDWARD M. LILLrn,citizens of the United States, residing at Ray, in the county of Pinaland State of Arizona, have invented certain new and useful Improvementsin Pneumatic Hammers, of which the following is a specication'.

This invention relates to pneumatic hammers, and aims primarily toprovide improvements in means for automatically rendering the hammerinactive or inoperative when vthe latter is released or disengaged fromthe work.

A further object of the invention is to provide in ya hammer employing arecipro# cating or movable mechanism :t'or directing and timing themotive Afluid in the piston chamber lends, improved means for utilizingthe motive Huid to force the controlling mechanism to the limit of itsstroke in one direction, whereby the motive Huid will be precluded'entrance to one end of the piston chamber, and means for exhausting thefluid pressure simultaneously at the opposite piston chamber end.

With these objects in view, together with others ywhich will appear asthe description proceeds, the invention resides in the novel formation,combination and `arrangement of parts, all as will be described morefully hereinafter, illustrated in the drawings, and particularly pointedout in the claims.

The invention will be best understood by reference to the accompanyingdrawings, wherein Figure 1 is a longitudinal sectional view takenthrough a pneumatic hammer of that type with which the invention isadapted more particularly for use;

Fig. 2 is a view similar to Fig. 1, the section being taken on aslightly -changed plane, and illustrating the position assumed by theparts when the tool is at work;

Fig. 3 is a view similar to Fig. 2 and illustrating the position assumedby the parts of the control mechanism when the latter have been moved torender the tool inoperative;

Fig. 4 is a sectional view taken upon line 4--4 Of Fig. 3;

Fig. 5 is a Jfragmentary sectional view similar to Fig.'v 4, with theparts` in the position they would occupy when the hammer is working;and` ,l Y

Fig. 6 isa slightly enlarged transverse of motive iuid to the oppositeends of the piston chamber, to; properly operate the piston. in thepresent illustration, there is shown a. familiar ltype of pneumatic hammer of this character for the .purpose of more clearly describing ytheparts and operations of the improved controlling device, but it is to beunderstood that the invention is not restricted to use exclusively i'n'connection with the speciiically constructed type or hammer, as it maywith equal facility, be used with hammers of other makes or typesemploying the reciprocating control valve.

Referring now more particularly to the drawing, the hammer cylinder isindicated at 10. This cylinder is provided at 'one 'en'd with a graspinghandle 11', within which 4is arranged a suitable valve operated by athumb lever or trigger 12 for controlling the flow of motive -iuid tothe cylinder. The forward 'or working end of the cylinder is providedwith a snap 'or tool 13, adapted when the tool is in operation, to headrivets.

The slide or reciprocating valve for controlling` theJ iiow of motiveuid to the piston chamber to operate the piston 14 is indicated at 15.i/Vhen the valve is in the position shown in Fig. 1, iiui'd pressure isadmitted to the rear end of the piston through the annular intake.passage 16, the pressure thus acting to drive the piston forwardly,while when moved to the limit of its rearward travel, the channel 16 is-closed, and motive fluid is admitted through the passage 17, port 18,groove 19, and passages 20 to the forward end of the cylinder to drivethe piston 14 rearwardly, as will be readily understood by referring tothe drawings. Hammers of this type are provided with a port 21,communicating at one end with the piston chamber at substantially themedial 'point of the latter, and at its vopposite e'n'd with arearwardly vextending passage 22 communicating at its rearward'extremity 'with a chamber 28 adjacent the slide valve and within whicha shoulder 24 on the slide-valve re'cipre'cates. As the .piston 14 movesfrward'ly-nnderithe ,impulse 'of pressure 'admitted to the'eai" leih'dvalve rearwardly. This movement ofthe valve admits motive fluidV to theforward end i. of the hammer, whereupon the piston is forced rearwardly.The means for further governing the movements of the piston or forexhausting the dead fluid, forming no part of the present invention,will not be further detailed.

In the present instance, the passage 22 1s 'extended forwardly beyondthe point of communication with the port 21, the said passage extensioncommunicating with the forward end of the hammer. Arranged for slidingmovement within this passage extension is a plunger valve or stem 25,the forward extremity .of which is held in contact with the rear face ofthe shoulder 26 formed upon the sna or tool by an expansion Spring 27,the latter being arranged within an enlarged portion of the forward partof the said passage. If desired, the forward extremity of the valve stem25 may be headed as shown at 28 to form a suitable abutment for thespring 27. The rear end of the stem 25 is provided with a centralchannel 29 having spaced right angularly disposed ports 30 and 31. Theport 30 is so positioned as to communicate with the port 21 when thevalve is moved to the Vlimit of its rearward travel,'while, when movedforwardly, the said port is disalined from the passage or port 21,thereby preventing motive fluid enterin the Vpassage 22. When in forwardposition, the angularlydisposed port 31 registers with a duct 32arranged in the cyl- .inder and in direct communication with a passage33 leadin from the main fluid passage in the bandiJ portion of thehammer. When in this latter position, fluid passes through the passage33, duct 32, opening or port 31, channel 29, passage 22 and into thechamber 23, forcing the valve 15 rearwardly to preclude the entrance ofmotive fluid to the rear end of the piston chamber. When in thisposition, the motive iuid is free to pass into the piston chamberthrough the passages 2O to the forward end of the tool.

To relieve the pressure which accumulates at the forward end of thepiston chamber when the valve 25'is moved forwardly, an exhaust port 35yis provided. This port extends laterally through the cylinder wall topermitof the escape of fluid to the atmosphere.V This port is also openor closed accordingl as the Snapor tool 13 is moved. A port c osing stem36 is arranged for slidf ing movement in a passage or bore 37 extendinginwardly from the forward end of the cylinder, the said boreintercepting the passage or exhaustport 35. The outer extremity of thestem 36'. is headed as at 38,

and is normally heldin engagement with the shoulder 26 on the Snap 13,by va spring 39. The stem 36 is of such length as to move entirely freeof the port 35 when the snap 1s Ymovedforwardly, but closes or obstructsthe exhaust port35 .when the snap 13 is forced inwardly. The stems 25and 36 arev limited in their inward and outward movement by screws 40.

In operation, the hammer is operated byV pressing the snap or toolthereon, against the work and depressing the trigger or thumb lever 12.backward and forward within the hammer cylinder to deliver to the snapor tool the proper blows. ,Should the hammer be removed from the worlrwithout severing'thev supply of motive fluid through theV valve of thecylinder to force the valve 15 rear-V wardly. This at oncecuts off thefluid supply at the rear end of the cylinder, but the iuid passes to theforward end through the passages 20, however, immediately upon forwardmovement of the snap13, the stem 36`is forced forwardly by the spring39, opening the exhaust passage 35 to permit of the pressure at theforward end ofthe hammer cylinder escaping toV the atmosphere. Furtheroperation of the hammer requires pressing -of the snap or tool againstthe work to force the stems 25 and 36 rearwardly to properly actuate thevalve on the stem 25, and to close the exhaust port 35.

F rom this construction, itis apparent that we have provided a simple,positive and thoroughly eflicient means for attaining the desired ends.A tool equipped with a device -of this character operates to preventblowing-out of the snap or tool upon failure of the control or throttlevalve to work,

rlhe piston 14 is drivenv whereby injury to persons in close proximityto the hammer is obviated, as well as breakage or derangement of thehammer.

. While the above is a description of the preferred embodiment of theinvention, it is 'Y apparent that various changes in the minor details,of construction and arrangement of parts may be resorted to withoutdeparting from the spirit of the invention ed when moved in onedirection to close the same and to admit fluid thereto, the said valvebeing operated by said snap, substantially as described.

2. In a pneumatic hammer, the combination with a reciprocating valve anda sliding snap, of a control valve in said hammer adapted when moved inone direction to `admit motive fluid to said reciprocating valve toforce the same to the limit of travel in one direction, an exhaust valvefor said hammer, and said control and exhaust valves being operated bysaid sliding snap, substantially as described.

3. In a pneumatic hammer having the usual longitudinally movable snap,the combination with the piston valve and the main air passage, the saidhammer having a duct connecting at one end with one end of said pistonvalve, the said main air passage, and said duct being in communicationwith each other, a stem moving longitudinally in said passage andextending over said communication, the said stem being hollow a shortdistance inwardly from one end, the said hollow portion of said stemhaving a port adapted to register with said communication, the movementsof said stem being controlled by the movement of said snap, and the saidport being in register with said communication when said snap is at thelimit of its inward movement, substantially `as described.

4L. In a pneumatic hammer having the usual longitudinally movable snap,the said hammer having an exhaust port at its outer end establishingcommunication between the interior of said hammer and the atmosphere,the said outer end of said hammer having a longitudinal passageintersecting said eX- haust port, a stein slidably arranged in saidpassage, a spring for holding said stem engaged with said snap, and therear end of said stem being extended .across said port to close the sameonly when the snap has moved to its outward limit, substantially asdescribed.

In testimony whereof we afHX our signatures in presence of twowitnesses.

HUGH F. JONES. JOHN E. LANE. EDWARD M. LILLIE.

Vitnesses J. M. BEATTIE, ROY BECK.

Copies oi this patent may be obtained for ve cents each, by addressingthe Commissioner of Patents,

Washington, D. C.

